package com.yupi.springbootinit.utils;

import cn.hutool.core.collection.CollUtil;
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.support.ExcelTypeEnum;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.ObjectUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.ResourceUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * excel 转换csv
 *
 * @return
 */
@Slf4j
public class ExcelUtils {
   public static String  excelToCsv(MultipartFile multipartFile)  {
//       File file=null;
//       try{
//           file=  ResourceUtils.getFile("classpath:测试数据.xlsx");
//       }
//       catch (FileNotFoundException e){
//           e.printStackTrace();
//       }
       //读取数据
       List<Map<Integer, String>> list = null;
       try {
           list = EasyExcel.read(multipartFile.getInputStream())
                   .excelType(ExcelTypeEnum.XLSX)
                   .sheet()
                   .headRowNumber(0)
                   .doReadSync();
       } catch (IOException e) {
           log.error("表格转换csv错误", e);
       }
       if(CollUtil.isEmpty(list)){
           return "";
       }
       //转换成csv数据
       StringBuilder stringBuilder = new StringBuilder();
       //读取表头
       LinkedHashMap<Integer, String> headerMap = (LinkedHashMap) list.get(0);
       List<String> headerList = headerMap.values().stream().filter(ObjectUtils::isNotEmpty).collect(Collectors.toList());
       stringBuilder.append(StringUtils.join(headerList, ",")).append("\n");

       //读取数据
       for(int i=1;i<list.size();i++){
           LinkedHashMap<Integer, String> dataMap = (LinkedHashMap) list.get(i);
           List<String> dataList = dataMap.values().stream().filter(ObjectUtils::isNotEmpty).collect(Collectors.toList());
           stringBuilder.append(StringUtils.join(dataList, ",")).append("\n");
//           System.out.println(StringUtils.join(dataList, ","));

       }
       return stringBuilder.toString();
   }
  public static void main(String[] args){
       excelToCsv(null);
  }
}
